the capacity of the air to hold water vapor

At 30 °C (86 °F), for example, a volume of air can contain up to 4 percent water vapour. At -40 °C (-40 °F), however, it can hold no more than 0.2 percent. The more the temperature more is the water holding capacity.

How does the capacity of air to hold water vapor vary?

The higher the temperature, the more water vapor a volume of air is capable of holding. Therefore, any change in temperature alters the volume’s water vapor capacity. As air warms, its capacity for holding water vapor increases; as it cools, the capacity decreases.

What determines the water vapor capacity of air?

Just as with saturation vapor pressure, the saturation mixing ratio, which specifies the maximum amount of water vapor that can be in the air, is determined by the air temperature … the higher the air temperature, the greater the saturation mixing ratio.

How does the capacity of air to hold water vapor change with temperature?

Hot air expands, and rises; cooled air contracts – gets denser – and sinks; and the ability of the air to hold water depends on its temperature. A given volume of air at 20°C (68°F) can hold twice the amount of water vapor than at 10°C (50°F).

What is the capacity of the air to hold water vapor?

Looking at your Capacity of Saturated Air table, you can see that as air temperatures rise, there is an increase in the ability of the air to hold moisture. At 80 degrees F the capacity of air increases to where it can hold 21.537 g/kg of water vapor.

Why does the amount of water vapor in the air vary?

The maximum amount of water vapor that can be in the air depends on the air temperature. Warmer air can hold more water vapor within it. That’s why the muggiest days usually happen at the height of summer heat. But as the temperature goes down, the air can hold less vapor and some of it turns into liquid water.

What determines the water vapor capacity of air?

The water vapor capacity of air is directly related to, and limited by, its temperature. The table below presents the water vapor capacity of a kilogram of air at various temperatures.

What two factors determine the amount of water vapor in the air?

The air temperature and the available humidity are two main factors affecting the water vapor content. If the temperature is high, more molecules will evaporate from liquids, and more water vapor will escape from the solution. The amount of water vapor in the air is variable because there are many different factors.

What is the water vapor capacity of air?

Looking at your Capacity of Saturated Air table, you can see that as air temperatures rise, there is an increase in the ability of the air to hold moisture. At 80 degrees F the capacity of air increases to where it can hold 21.537 g/kg of water vapor.

What is used to determine the amount of water vapour in air?

Humidity is the amount of water vapor in the air. The vapor content of air is measured with devices known as hygrometers. The measurements are usually expressed as specific humidity or percent relative humidity.

What is water vapor capacity dependent on?

The higher the temperature, the more water vapor a volume of air is capable of holding. Therefore, any change in temperature alters the volume’s water vapor capacity. As air warms, its capacity for holding water vapor increases; as it cools, the capacity decreases.